Spintronics may Improve Data Life One Million Fold
Credit: Dr. Alan Drew 2008
The Read head of a typical computer hard drive takes advantage of Giant Magnetoresistance to carefully read changes in the external magnetic field and therefore your desired data. Most people, however, don’t know that this process actually involves determining the spin of electrons. While most electronics simply communicate information by reading the charge, magnetic read heads communicate using the electron’s intrinsic magnetic field (spin). This is an example of spintronics.
What is Spintronics?
Yup it’s a combination of “spin” and “electronics.” However, it is also the basis for many of our electronic components today. Dr. Alan Drew from Queen Mary’s Department of Physics and the University of Freiburg, Switzerland and several colleagues decided to investigate exactly how spin travels through the read head.
A typical read head is comprised of a spinvalve, two magnetic layers sandwiching one non-magnetic layer, that facilitates the transfer of this spin information. They concerned themselves with spin transfer in the middle, non-magnetic layer. Dr. Drew’s team is the first ever to measure exactly how magnetic polarization is transferred in materials similar to those in magnetic read heads.
These measurements are difficult due to the extremely small scales of magnetic fields within the materials. Their team had to use low-energy muons to gauge internal magnetic fields. Dr. Morenzoni, from the Paul Scherrer Institute, said, “The muons have a high energy and must be slowed down before they can be used in the experiment and the equipment we used to do this is unique – PSI is the only source of ’slow’ muons in the world, and the only equipment that can measure depth resolved magnetism.”
Future Goals and Organic Spintronics
This achievement deepens our understanding of how read heads work and of spintronics in general. Dr. Drew was optimistic about the general applicability stating, “Spintronics promise low-power circuits, possibly at the quantum level, and the possibility of combining communication, memory and logic on the same chip. The efficient transfer of spin in these devices remains one of the most difficult challenges facing physicists.”
Organic spintronic devices are those devices made from organic material capable of spintronic behavior. The devices are also capable of preserving magnetic information for a very long time, over one million times greater than today’s technology, and are very inexpensive to produce, according to Dr. Drew. His research, which used organic spintronics, points to new and exciting material combinations that can be used in similar ways. “These new materials have the potential to create an entirely new generation of spin-enabled devices,” concluded Dr. Drew.
Sources:
http://www.sciencedaily.com/releases/2008/11/081124102710.htm
Drew et al. Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation. Nature Materials, 2008; DOI: 10.1038/nmat2333
This entry was posted on Saturday, November 29th, 2008 at 3:11 pm and is filed under Condensed Matter. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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